Thinking in your head feels clear until you try to write it down. Then the gaps appear. The fuzzy logic. The missing connections. The assumptions you did not know you were making.
Writing forces clarity. The page demands specificity that the mind allows you to skip. If you cannot write it clearly, you do not understand it clearly.
This is why writing is thinking. Not just recording thoughts, but developing them. The act of writing reveals what you know and exposes what you do not.
What idea in your head would benefit from being written down?